package Sort;
    import java.io.IOException;
    import org.apache.hadoop.io.DoubleWritable;
    import org.apache.hadoop.io.LongWritable;
    import org.apache.hadoop.io.Text;
    import org.apache.hadoop.mapreduce.Mapper;
    public class sortmapper extends                  Mapper<LongWritable,Text,Text,DoubleWritable> {
        public void map(Text key, Iterable<DoubleWritable> value, Context                            context) throws IOException, InterruptedException {
            String line = value.toString();
            String subId = line.substring(15, 26);
            Double bytes = Double.parseDouble(line.substring(45, 56));
            if (bytes == null) 
                bytes = 0.0;
            context.write(new Text(subId),new DoubleWritable(bytes));
        }
    }

这是我写的mapper方法，但是我得到了上面的错误。